Cited by 128Quantum Information and CryptographyQuantum Computing Algorithms and ArchitectureQuantum many-body systems

The DOI matches its Crossref record; 30 of the 30 references it cites were found in a registry or an index; none of the 19 sources its claims cite is checked for support yet.

Quantum speed limit for perfect state transfer in one dimension

Open access
Yung, Man-Hong·2006·Physical Review A

Abstract

The basic idea of spin-chain engineering for perfect quantum state transfer (QST) is to find a set of coupling constants in the Hamiltonian such that a particular state initially encoded on one site will evolve freely to the opposite site without any dynamical controls. The minimal possible evolution time represents a speed limit for QST. We prove that the optimal solution is the one simulating the precession of a spin in a static magnetic field. We also argue that, at least for solid-state systems where interactions are local, it is more realistic to characterize the computation power by the couplings than the initial energy.

Overview

AI snapshot

Written from the paper’s full text.

TL;DR

The paper proves that the fastest possible perfect quantum state transfer (QST) through a one-dimensional engineered spin chain is achieved by the linear eigenvalue spectrum, equivalent to spin precession in a static magnetic field. It establishes a quantum speed limit for QST and argues that, for local solid-state systems, computational power is better characterized by Hamiltonian couplings than by initial energy.

Key findings

  • The optimal perfect-QST solution is the linear spectrum \(E_k = -(N-1)/2 + k - 1\), \(k=1,\dots,N\), which gives perfect transfer at \(\tau=\pi\) and is the same coupling set as spin precession in a static magnetic field.
  • The paper proves \(\eta \ge 1\) for all engineered spin chains, where \(\eta\) compares evolution time under normalized maximum coupling to the linear reference chain, so the linear solution is optimal and sets the one-dimensional QST speed limit.
  • Table I compares efficiencies: linear \(\eta=1\); quadratic \(\eta=q(2\alpha+N)\); gapped linear I \(\eta=(1+4q/N)\); gapped linear II \(\eta=q\) for \(N=4\) only; cosine \(\eta=14.0\) for \(N=31\) with no analytic solution given.
  • Engineered chains can be roughly twice as fast as a series-of-swaps protocol: \(1 \le \eta_{\rm sos} < 2\) for \(N \ge 2\).
  • The paper argues that the Margolus-Levitin theorem, based on initial energy, does not give an appropriate bound for transfer to a particular state; for local solid-state systems, couplings in the Hamiltonian are a more realistic measure of computational power.

Methods

  • Theoretical study of a one-dimensional spin-1/2 chain Hamiltonian with site-dependent couplings \(\omega_j\) and \(\lambda_j\), restricted to the single-excitation subspace and mirror-symmetric chains.
  • Perfect QST is formulated as an inverse eigenvalue problem: given an eigenvalue spectrum satisfying the transfer condition, the couplings are uniquely determined.
  • The proof uses the Hellmann-Feynman theorem, eigenvalue interlacing, trace differences between symmetric subspaces, and a recursive relation for \(\omega_m\) to show \(\omega_{\max} \ge \tilde{\omega}_{\max}\) for even and odd \(N\).

Limitations

  • The paper states that the speed limit could be overcome if not confined to nearest-neighbor interactions in one dimension, by increasing either network complexity or Hamiltonian complexity; details are deferred elsewhere.
  • The comparison table includes restricted cases: gapped linear II is for \(N=4\) only, and the cosine spectrum is for \(N=31\) with no analytic solution given.
  • The proof relies on mirror-symmetric chains and non-degenerate eigenvalues; the coupling-based computational-power argument is explicitly framed for solid-state systems where interactions are local.

Model-written summary. Check it against the paper before relying on it.

Integrity signals

Registry

Crossref · 10.1103/physreva.74.030303

Cites

30 of 30 references verified0 citation errors · 0 not checkable

Statistics

Nothing to recompute.

Verification

Claims the paper makes

15 Not checked yet · 8 Own interpretation · 7 No basis given

Verify all 19 references — free account

Show all 16 claims

  • It may state two separate claims as one. 6
  • Probably not a substantial claim. 9
14 of 14
  • The paper relies on this without support.

    The SOS protocol necessarily introduces errors due to dynamical controls, causing the fidelity of transferred states to decay exponentially as the number of swaps increases.

    “However, even in the absence of decoherence, the intrinsic problem of this protocol is that each swap would necessarily introduce some errors due to dynamical controls, the fidelity of the transferred states would therefore decay exponentially as the number of swaps increases.”
  • The authors state this as an assumption.

    The terms λ_j play no role in the eigenvalue spectrum except a constant shift.

    “Of course, this argument is based on the assumption that the terms λ j play no role in the eigenvalue spectrum except a constant shift.”
  • The authors state this as an assumption.

    In the SOS protocol, interactions between pairs of qubits can be arbitrarily switched on and off.

    “In these scenarios, a typical assumption usually made is that the interactions between pairs of qubits can be arbitrarily switched on and off [4, 5].”
  • The paper relies on this without support.

    The relative phase factor in the transferred state can be corrected by local operations and is usually ignored.

    “Although the transferred state in general differs from the input state by a relative phase factor, i.e. αe iφ | 1 〉 + β | 0 〉 , the phase factor could be corrected by some local operations and is thus usually ignored.”
4 of 4

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Citations

Cites

Cited by

Sorted by citations

See all 128

Metadata

Authors
Yung, M.-H.
Affiliations
University of Illinois Urbana-Champaign (US)
Corresponding author
Yung, Man-Hong
Venue
Physical Review A
Published
2006-09-14
Volume
74
Issue
3
ISSN
  • 0556-2791 (ISSN-L)
  • 1050-2947
  • 1094-1622
OpenAlex
W2073278667
Cited by
128
References
30
Citations by year
2026: 4 · 2025: 5 · 2024: 5 · 2023: 4 · 2022: 11 · 2021: 7 · 2020: 5 · 2019: 4 · 2018: 8 · 2017: 10 · 2016: 9 · 2015: 6 · 2014: 3 · 2013: 6 · 2012: 6
FWCI
8.70
Type
journal article
Language
en
Open access
Locations
  • Physical Review A (publishedVersion)
  • arXiv (Cornell University) (submittedVersion)
  • CERN Document Server (European Organization for Nuclear Research) (submittedVersion)
  • arXiv (Cornell University)
Topics
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum Information and Cryptography
  • Physical Sciences › Computer Science › Artificial Intelligence › Quantum Computing Algorithms and Architecture
  • Physical Sciences › Physics and Astronomy › Atomic and Molecular Physics, and Optics › Quantum many-body systems
Keywords
quantum speed limit, perfect state transfer, spin chains, one-dimensional systems, local interactions, solid-state quantum computing

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

A language model drew the claims from the paper on 2026-10-06, under version 3 of the claim definition (model deepseek-v4.1-flash, prompt extract-v3).

A second model labelled each claim on 2026-10-06 (model jev-1.13-20260917, definition revision gold-guideline-v0.2).

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review